Vol. 11, Issue 4, Part B (2025)

Background: The efficiency of diamond burs is critical for crown preparation in fixed prosthodontics. Progressive wear of burs compromises cutting ability and affects the quality of prepared surfaces.

Objective: To microscopically evaluate the surface changes in diamond burs after one and three crown preparations, and to correlate these changes with their expected clinical performance.

Methods: Fresh diamond burs and burs used for one and three crown preparations were examined under a digital microscope. Microscopic surface features were documented and compared. Observations focused on crystal sharpness, surface clogging, and debris retention.

Results: Fresh burs demonstrated sharp, evenly distributed crystals. After one use, partial wear and early clogging were evident. After three uses, severe particle loss, flattened surfaces, and significant clogging were observed. These changes correlate with reduced cutting efficiency, greater heat generation, and rougher tooth surfaces.

Conclusion: Diamond burs undergo rapid microscopic deterioration after repeated use. Replacement after two to three crown preparations is recommended to maintain cutting efficiency and ensure optimal surface finish.